Method and system for finding approximate matches in database

ABSTRACT

Entertainment content complementary to a musical recording is delivered to a user&#39;s computer by means of a computer network link. The user employs a browser to access the computer network. A plug-in for the browser is able to control an audio CD or other device for playing the musical recording. A script stored on the remote computer accessed over the network is downloaded. The script synchronizes the delivery of the complementary entertainment content with the play of the musical recording.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. patent application Ser. No. 08/838,082filed Apr. 15, 1997, now U.S. Pat. No. 5,987,525, issued on Nov. 16,1999.

BACKGROUND

1. Field of the Invention

This invention pertains to the field of computer networking, and moreparticularly to the use of network protocols to provide services tousers which are related to audio recordings.

2. Related Art

Over the past few years, on-line services have experienced explosivegrowth and have become a major new form of entertainment. Alongside thisnew entertainment, more traditional forms such as musical recordingshave continued to be consumed on a massive scale.

The traditional experience of the musical recording is listening by asmall group of persons gathered together in a room. The music fills theroom acoustically, but there is little associated visual content, andthere is only a limited interaction with the recording, consistingessentially of deciding which tracks to play and performing simpletransformations on the recorded sound, such as setting the volume orapplying an audio equalizer. This traditional experience dates back tothe early age of 78 r.p.m. musical recordings almost a century ago.

The traditional production of a musical recording complements thetraditional experience of the recording. The recording is produced in anumber of recording sessions, subject to careful mixing and editing, andthen released to the public. At that point, the recording is in a fixedform, nowadays an audio CD, whose purpose is to record as faithfully aspossible the final sonic experience designed by its authors, themusicians, producer, and recording engineers.

Music videos have supplemented the traditional experience of musicalrecordings by allowing the association of visual content with tracks ofsuch a recording. In practice, however, music videos have beenbroadcast, with all the problems of lack of user control which thatimplies, and they have not contributed to interactivity or participationby the consumer.

On-line services offer opportunities for enriching the experienceassociated with musical recordings. The present invention is addressedto computer programs, systems, and protocols which can fulfil thispromise.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide computerprograms, systems, and protocols which allow producers to deliverentertainment complementary to musical recordings by means of on-lineservices such as the Internet. It is a further object of this inventionto provide computer programs, systems, and protocols which allow suchcomplementary entertainment to be meaningfully interactive for theconsumer, such that the consumer can also be a creator of theexperience.

It is a further object of the invention to achieve the foregoing objectsby means of implementations designed to attain integration with existingenvironments and programs, particularly on the Internet, while retainingthe flexibility to adapt to the continuing evolution of standards foron-line services.

In one aspect of the invention, software is provided which permits acomputer program running on a remote host to control a compact disk (CD)player, DVD player, or the like on a user's computer. (For convenience,we use the term "CD player" to refer also to DVD players and similardevices.) The software is designed to permit the remote host both toinitiate actions on the CD player and to become aware actions which theuser has initiated by other control means, such as the buttons on the CDplayer's front panel or a different CD player control program. Thisaspect of the invention is a building-block for the provision ofcomplementary entertainment for musical recordings when those recordingsare fixed in the prevailing contemporary form, the audio CD.

In a second aspect of the invention, visual content, includinginteractive content, may be delivered over an on-line service in such away that it is synchronized to the delivery of content from a musicalrecording. Such visual content may, for example, be synchronized to theplaying of an audio CD in the user's computer. The visual content isthematically linked to the musical recording, for example in the mannerof a music video.

In a third aspect of the invention, a method is provided for assigning aunique identifier to musical recordings consisting of a number oftracks. A unique identifier is a useful complement to the delivery ofvisual content in conjunction with the playing of an audio CD in that itallows the software which delivers the visual content to be sure thatthe audio CD is in fact the correct CD to which the visual contentcorresponds. If the visual content is designed, for example, toaccompany the Rosary Sonatas of Heinrich Ignaz Franz Biber, it wouldpresumably not function well if the CD in the user's player were thesoundtrack for the film Mary Poppins. The unique identifier also allowsa CD to be used as a key to access a premium Web area. Furthermore, theunique identifier can allow the user to be directed to an area of theWeb corresponding to the CD which is in the user's machine.

In a fourth aspect of the invention, the immensely popular on-lineservice generally referred to as a "chat room" may be enhanced by meansof a link to a musical recording to which all persons in the room arelistening. The chat room experience as it exists today in on-lineservices has a disembodied quality by comparison with traditionalface-to-face social encounters, in which there are identifiablesurroundings. The only common experience to the chat users today are thewords of the chat as they fly by on a computer screen, and perhaps theuser icons ("avatars") or other visual content occupying a small spaceon the screen. The use of a musical recording in conjunction with a chatroom opens up the possibility of restoring to the -experience a degreeof the shared ambience of traditional social encounters. Furthermore,the musical recording offers a focal point that allows chat-seekers togroup together by means of shared interests in a particular type ofrecording.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the environment in which the preferredembodiment operates.

FIG. 2 is a flowchart of the synchronization code of the invention.

FIG. 3 is a flowchart of the sequence of operations for connection to achat room focused on a musical recording.

DESCRIPTION OF PREFERRED EMBODIMENTS

1. Introduction

The preferred embodiment of this invention operates on the World WideWeb. The software implementation environment provided by the World WideWeb is described in a number of books, for example, John December & MarkGinsburg, HTML 3.2 and CGI Unleashed (1996). The World Wide Web is basedon a network protocol called HTTP (hypertext transfer protocol), whichis described in T. Berners-Lee et al., Hypertext TransferProtocol--HTTP/1.0 (Internet Request for Comments No. 1945, 1996). TheHTTP protocol must be run atop a general connection-oriented protocol,which today is generally TCP/IP, described in Douglas E. Comer,Internetworking with TCP/IP (3d ed. 1995). However, the inventiondescribed here is not limited to HTTP running over any particular kindof network software or hardware. The principles of the invention applyto other protocols for access to remote information that may come tocompete with or supplant HTTP.

As shown in FIG. 1, a Web user sits at his or her computer and runs acomputer program called a browser. The browser sends out HTTP requeststo other computers, referred to as servers. In requests, particularitems of data, referred to as resources, which are available on servers,are referred to by means of uniform resource locators (URL's), characterstrings in a particular format defined in Berners-Lee et al., supra. AURL includes both an identification of the server and an identificationof a particular item of data within the server. Reacting to therequests, the servers return responses to the user's browser, and thebrowser acts upon those responses, generally by displaying some sort ofcontent to the user.

The content portion of the responses can be a "Web page," expressed inthe hypertext markup language (HTML). That language allows one toexpress content consisting of text interspersed with bitmap-formatimages and links (also known as anchors and hyperlinks). The links arefurther URL's to which the browser may, at the user's prompting, sendfurther requests.

The responses can also include more complex commands to be interpretedby the browser, e.g., commands which result in an animation. HTML itselfdoes not define complex commands, but rather they are considered tobelong to separately-defined scripting languages, of which the two mostcommon ones are JavaScript and VBScript.

In addition to extending the function of the browser by means of codewritten in a scripting language, it is also possible to extend thefunction of a browser with compiled code. Such compiled code is referredto as a "plug-in." The precise protocol for writing a plug-in isdependent on the particular browser. Plug-ins for the Microsoft browserare referred to by the name of ActiveX controls.

Plug-ins may be very complex. A plug-in which may advantageously be usedin connection with the invention is Shockwave from Macromedia. Itpermits animations which are part of a server response to be downloadedand played to the user. Shockwave defines its own scripting languagecalled Lingo. Lingo scripts are contained within the downloadableanimations which the Shockwave plug-in can play. The general format of aShockwave animation is a timeline consisting of a series of frames,together with a number of visual objects which appear, perform motions,and disappear at particular frames within the timeline. To achieve morecomplex effects within a Shockwave animation, Lingo scripts may beinvoked in addition to predefined visual objects.

2. Command Plug-In

A preferred embodiment of the invention employs a plug-in, referred toas the command plug-in, which provides to a scripting language theability to command in a detailed fashion the playing of a musicalrecording. The command plug-in should provide, at a minimum, thefollowing basic functions:

(1) Start and stop play.

(2) Get current track and position within the track.

(3) Seek to a track and a position within the track.

(4) Get and set volume.

(5) Get information regarding the CD (e.g., the number of tracks, theirlengths, the pauses between tracks).

(6) Get information regarding the capabilities of the CD drive.

Other functions may be provided, limited only by what the underlyingoperating system services are able to provide.

The command plug-in is preferably written in a conventional programminglanguage such as C++. The plug in must conform to the existing standardsfor plug-ins, such as those required of Microsoft ActiveX objects. Inorder to obtain the information and carry out the functions which thecommand plug-in makes available to the scripting language, the commandplug-in relies on functions which provide control and informationregarding the playing musical recording. These functions will depend onthe precise source of the recording. If, as in the currently preferredembodiment, the recording is being played on an audio CD in the computerCD player, and if the browser is running under Microsoft Windows 3.1 orWindows 95, these functions would be the MCI functions, which form apart of the Win32 application programming interface. These functions aredocumented, for example, in Microsoft Wn32 Programmer's Reference.Different functions may be provided by streaming audio receivers, as forexample receivers which capture audio which is coming into the user'scomputer over a network connection in a suitable audio encoding formatsuch as MPEG.

An important point to note about the implementation of the commandplug-in is that the operations which it carries out, as for exampleseeks, may take times on the order of a second. It is undesirable forthe command-plug in to retain control of the machine during thatinterval, so it is important that the plug-in relinquish control of themachine to the browser whenever a lengthy operation is undertaken, andreport on the results of the operation via the asynchronous eventhandling capability used in the common scripting languages.

Given the above summary of the functions which the command plug-inprovides, a general knowledge of how to write plug-ins (e.g., of how towrite ActiveX objects), and a knowledge of the relevant applicationprogramming interface for controlling the play of the musical recording(e.g., MCI in Win32), a person skilled in the art could readily andwithout undue experimentation develop an actual working command plug-in.For this reason, further details of how the command plug-in isimplemented are not provided here.

3. Synchronization

The existence of a command plug-in providing the functions listed aboveto a scripting language is a foundation on which entertainmentcomplementary to a musical recording may be constructed. In particular,it is possible to devise, building on this foundation, a method forsynchronizing the display of visual content by means of the scriptinglanguage with the events which are occurring on the audio CD.

In a preferred embodiment of the invention, the synchronization of thevisual content to the audio CD proceeds as follows. The visual contentis provided by means of a Shockwave animation, which is downloaded fromthe server and displayed for the user by means of a Shockwave plug-in.This downloading may take place before the animation is displayed, oralternatively it make take place as the animation is being displayed,provided the user's connection to the network is fast enough to supportdownload at an appropriate speed. The downloading is a function providedby the Shockwave plug-in itself.

As the Shockwave animation is played, a Lingo script executes each timea frame finishes displaying. The Lingo script contains a description ofthe relationship which should exist between frames of the animation andsegments of the musical recording, identified by track number and bytime. The Lingo script determines, by means of the command plug-indescribed above, at which track and time the play of the audio CD is. Itthen refers to the description in order to determine which frames of theanimation correspond to that portion of the audio CD. If the currentframe is not one of those frames, the Lingo script resets the time lineof the animation so that the animation will begin to play at the framewhich corresponds to the current position of the audio CD. This permitsthe visual content to catch up if it ever lags the CD, for examplebecause downloading from the network has fallen behind, because theuser's computer lacks the cycles to play the animation at full speed, orbecause the user has fast forwarded the CD.

In a variant form of this synchronization algorithm (shown in FIG. 2),the frames of the animation are arranged into groups of contiguousframes. A correspondence is established between each such group offrames and a particular segment of the audio recording (box 200 in FIG.2). At the end of each frame of the animation, the audio play positionis determined (box 210). A test is done to determine whether the audioplay position is within the segment of the recording that corresponds tothe group of frames to which the next sequential frame belongs (box215). If the audio play position is within that segment, the playback ofthe animation proceeds with that next frame (box 230). If the audio playposition is not within that segment, then the playback of the animationis advanced to the frame corresponding to where the audio is (boxes 220and 225).

4. Unique Identifiers for Audio CDs

A further aspect of the invention is the ability, by making use of thecommand plug-in, to provide a technique for establishing a uniqueidentifier for an audio CD which is located in the user's CD player. Theunique identifier may be based on the number and lengths of the tracks(measured in blocks, i.e., 1/75ths of a second), so that the identifierwould be a concatenation of these lengths. In practice, however, it isdesirable to have a somewhat shorter identifier, so the uniqueidentifier is preferably the concatenation of the track lengthsexpressed in a fairly coarse unit, such as 1/4th of a second.

Appendix A contains source code, written in C, for a fuzzy comparisonalgorithm suitable for determining whether two audio CDs are exactly orapproximately the same. The fuzzy comparison algorithm proceeds asfollows. For each of the two audio CDs to be compared, one determinesthe lengths of all the tracks in the recordings in milliseconds. Onethen shifts all track lengths to the right by eight bits, in effectperforming a truncating division by 2⁸ =256. One then goes through bothof the recordings track by track, accumulating as one proceeds twonumbers, the match total and the match error. These numbers are bothinitialized to zero at the start of the comparison. For each of thetracks, one increments the match total by the shifted length of thattrack in the first CD to be compared, and one increments the match errorby the absolute value of the difference between the shifted lengths ofthe track in the two CDs. When one gets to the last track in the CD withthe fewer number of tracks, one continues with the tracks in the otherCD, incrementing both the match total and the match error by the shiftedlengths of those tracks. Following these steps of going through thetracks, the algorithm then divides the match error by the match number,subtracts the resulting quotient from 1, and converts the difference toa percentage which is indicative of how well the two CDs match.

Appendix B Contains source code, written in C, for a comparisonalgorithm suitable for determining whether two audio CDs are exactly thesame. The algorithm generates from the number of tracks, the tracklengths, and the start and end times of the tracks an 8-byte value. Thehigh order 4 bytes are obtained by summing the start and end times ofall tracks, expressed in milliseconds. The low order 4 bytes areobtained by summing the lengths of all tracks expressed in milliseconds,shifting the sum left ten bits, and adding the number of tracks.

A unique identifier for a musical recording may be employed as adatabase key. A site may maintain a database of information about CDs,for example information about all CDs issued by the particular recordcompany can be maintained on that record company's site. There arevarious alternative ways for users to navigate this information. Forexample, they could use a Web page containing many hyperlinks as a tableof contents, or they could use a conventional search engine. A third wayof searching which is enabled by the unique identifier of the inventionis for there to be Web page which invites the user to place in thecomputer's CD drive the CD about which he or she is seeking information.Upon detection of the presence of the CD in the drive, a script in theWeb page computes the unique identifier corresponding to the CD andsends it to the server. The server then displays information about theCD retrieved from a database on the basis of that unique identifier.This information may include a Web address (URL) that is related to- theaudio CD (e.g., that of the artists' home page), simple data such as thenames of the songs, and also complementary entertainment, includingpotentially photographs (e.g., of the band), artwork, animations, andvideo clips. It is also possible to arrange things so that, when theuser inserts an audio CD into the computer, (i) the Web browser islaunched if not already running, (ii) the browser computes the CD'sunique identifier and from that unique identifier derives a URL, and(iii) the browser does an HTTP get transaction on that URL.

An alternative application of unique identifiers for musical recordingsis to employ an audio CD as a key for entering into a premium area ofthe Web. There are presently premium areas of the Web to which peopleare admitted by subscription. A simple form of admission based on theunique identifier is to require, before accessing a particular area ofthe Web, that the user place in his or her CD drive a particular CD, ora CD published by a particular company or containing the music of aparticular band or artist. This is readily accomplished by means of ascript which invokes the functions provided by the command plug-in andcomputes a unique identifier.

5. Chat Rooms Connected With Musical Recordings

A third aspect of the invention is the connection of chat rooms withmusical recordings. The goal is to provide all participants in a chatroom with the same music at approximately the same time.

The prevailing network protocol for chat services is Interney Relay Chat(IRC), described J. Oikarinen & D. Reed, Internet Relay Chat Protocol(Internet Request for Comments No. 1459, 1993). In this protocol, whenone becomes a client of a chat server, one sends the name of a chatroom. The chat server receives messages from all of its of clients andrelays the messages sent in by one client to all the other clientsconnected in the same room as that client. The messages which a clientsends are typically typed in by the user who is running the client, andthe messages which a client receives are typically displayed for theuser who is running the client to read.

In a preferred embodiment of the invention, a chat client is customizedby means of a plug-in, which we will call the chat plug-in. The chatclient is started up by a browser as follows (see FIG. 3). The userconnects by means of the browser to a central Web page (box 300) which,upon being downloaded, asks that the user insert a CD into his or herplayer (box 305). A unique identifier of the CD is computed andcommunicated back to the server by using the control plug-in describedabove under the command of a script in the central Web page (box 310).The server then employs the unique identifier to determine whether ithas a chat room focused on the CD (box 315). This step may be carriedout by looking the unique identifier up in a database using techniqueswell known in the art. There exists a vast literature on connecting Webpages to databases, e.g., December & Ginsburg, supra, chapter 21. If achat room focused on the CD exists or can be created, the serverresponds with the name of that chat room, and the browser starts up achat client on the user's computer as a client of that chat room (box320).

The chat room's name is set by the server to contain information aboutthe track which the CD is playing in the other chat room clients'machines and the time at which the track started to play, as well asabout the volume at which the CD is playing. The chat client plug-inemploys that information to direct the control plug-in to set the CD inthe user's computer to play in such a manner that it is approximatelysynchronized to the CD which is playing in the other chat room clients'machines (box 320).

Each user in the chat room is able to control the CD which is playing inhis or her machine. Control actions result in the chat plug-in sendingmessages to the chat server which describe the control action beingtaken (box 325). For example, such messages may indicate a change in theposition of the CD, a change in the volume, or the ejection of the CD toreplace it with another. The chat plug-ins running on the other users'machines, upon seeing a message of this kind, replicate the action (asfar as possible) on the other users' machines by using the controlplug-in described above (box 330).

In a further aspect of the invention, a chat room focused on aparticular musical recording might allow for a voting procedure toselect particular tracks. A simple voting procedure would be for eachchat plug-in to act upon a change message of the kind described in thepreceding paragraph only when it sees two identical consecutive changemessages. This would mean that in order to change the track which isbeing played, it would be necessary for two users to change to thattrack. The number two may be replaced by a higher number.

In a further aspect of the invention the messages delivered to the usersof a chat can be driven from a text file rather than manual typing. Thiswould allow a pre-recorded experience to be played back for a group ofchat users. Such a technique may be used to create a pre-recorded,narrated tour of an audio CD.

An important advantage of the preferred embodiment as described above isthat it may be used with any chat server software which supports theminimal functionality required by Internet Relay Chat or by a protocolproviding similar minimum chat service. The additional software requiredis located in the chat client plug-in and in the central Web page, withits connection to a database of CD information.

                  APPENDIX A                                                      ______________________________________                                        /*                                                                             * FUZZY CD ID                                                                 * (c) 1996 ION                                                                *                                                                             *                                                                             * by Ty Roberts                                                              */                                                                            #include <stdio.h>                                                            #include <stdlib.h>                                                           #include <time.h>                                                             struct fuzzyCDid {                                                             short       numTracks; //start time in milliseconds                          unsigned short  fuzzlength[100];                                              };                                                                            typedef struct fuzzyCDid fuzzyCdid, *fuzzyCdidPtr;                            // structure of a cd track with all times stored in milliseconds              struct cdtrack {                                                              long    beginMs; // start time in milliseconds                                long    endMs;     // end time in milliseconds                                long    lengthMs;                                                                              // length in milliseconds                                    };                                                                            typedef struct cdtrack cdtrack, *cdTrackPtr;                                  struct cd {                                                                   short   numTracks;                                                            cdtrack   track[100];                                                         };                                                                            typedef struct cd cd, *cdPtr;                                                 void CreateFuzzyId( fuzzy CDidPtr fid, cdPtr cd );                            float FuzzyMatch( fuzzyCDidPtr fid1, fuzzyCDidPtr fid2 );                     // SUBROUTINES                                                                void CreateFuzzyId( fuzzy CDidPtrfid, cdPtr cd )                              long    i;                                                                    // first copy in the number of tracks                                         fid->numTracks = cd->numTracks;                                               for(i=0;i<fid->numTracks;i++) {                                               // shift left and create a MSB length thats not exact                         fid->fuzzlength[i] = (short)(cd->track[i].lengthMs>>8);                       }                                                                             }                                                                             float FuzzyMatch( fuzzyCDidPtr fid1, fuzzyCDidPtr fid2)                       {                                                                             long      fidmatcherr = 0, fidmatchtotal = 0;                                 short    i, trackcnt;                                                         float    matchpercent;                                                        // find the larger number of tracks                                           trackcnt = fid1->numTracks<fid2->numTracks ? fid2->numTracks:                 fid1->numTracks;                                                              // cycle thru the tracks accumulating error and total comparedtimes           for(i=0;i<trackcnt;i++) {                                                     if ((i < fid1->numTracks) && (i < fid2->numTracks)) {                                 fidmatcherr += abs(fid1->fuzzlength[i]                                       fid2->fuzzlength[i]);                                                         fidmatchtotal += fid1->fuzzlength[i];                                  } else if (i >= fid2->numTracks) {                                                    fidmatcherr += fid1->fuzzlength[i];                                          fidmatchtotal += fid1->fuzzlength[i];                                  } else if (i >= fid1->numTracks) {                                                    fidmatcherr += fid2->fuzzlength[i];                                          fidmatchtotal += fid2->fuzzlength[i];                                  }                                                                             }                                                                             if (fidmatcherr > 0) {                                                        matchpercent = 100 - (((float)fidmatcherr/                                    (float)fidmatchtotal)*100);                                                   } else {                                                                      matchpercent = 100;                                                           }                                                                             return matchpercent;                                                          }                                                                             void main(void)                                                               {                                                                             short i;                                                                      float matchpercent;                                                           // create global structures for two complete cds with up to 100 tracks        cd    cd2id;                                                                  fuzzyCDid fidcd2id;                                                           cd    cdFromDB;                                                               fuzzyCDid fidcdFromDB;                                                        printf("Test #1 will compare two CDs that are exactly the                     same\n\n");                                               // put in some test values for the cd track lengths                           // since these are in ms, its basically 6000 = 1 minutes                      cd2id.track[0]lengthMs = 121323;                                              cd2id.track[1]lengthMs = 234565;                                              cd2id.track[2]lengthMs = 566437;                                              cd2id.track[3]lengthMs = 245120;                                              cd2id.track[4]lengthMs = 20000;                                               cd2id.track[5]lengthMs = 120386;                                              cd2id.track[6]lengthMs = 323453;                                              cd2id.numTracks = 7;                                                          for(i=1;i<cd2id.numTracks;i++){                                               printf("CD #1: Track = %d length in minutes = %f\n";                i, (float)cd2id.track[i].lengthMs/60000.0);                                   }                                                                             printf("\n");                                                       cdFromDB.track[0]lengthMs = 121323;                                           cdFromDB.track[1]lengthMs = 234565;                                           cdFromDB.track[2]lengthMs = 566437;                                           cdFromDB.track[3]lengthMs = 245120;                                           cdFromDB.track[4]lengthMs = 20000;                                            cdFromDB.track[5]lengthMs = 120386;                                           cdFromDB.track[6]lengthMs = 323453;                                           cdFromDB.numTracks = 7;                                                       for(i=1;i<cdFromDB.numTracks;i++){                                            printf("CD #2: Track = %d length in minutes = %f\n",                i, (float)cdFromDB.track[i].lengthMs/60000.0);                                }                                                                             CreateFuzzyId( &fidcd2id, &cd2id );                                           CreateFuzzyId( &fidcdFromDB, &cdFromDB );                                     matchpercent = FuzzyMatch( &fidcd2id, &fidcdFromDB );                         printf ("The cd's matchpercent was computed as=%f", matchpercent);            printf("\n");                                                       printf("\n");                                                       printf("Test #2 will compare two cd that are nearly the                       same\nexcept                                                        they have                                                                     diffent # of tracks \n");                                           // put in some test values for the cd track lengths                           // since these are in ms, its basically 6000 = 1 minutes                      cd2id.track[0]lengthMs = 121323;                                              cd2id.track[1]lengthMs = 234565;                                              cd2id.track[2]lengthMs = 566437;                                              cd2id.track[3]lengthMs = 245120;                                              cd2id.track[4]lengthMs = 20000;                                               cd2id.track[5]lengthMs = 120386;                                              cd2id.track[6]lengthMs = 323453;                                              cd2id.numTracks = 7;                                                          for(i=1;i<cd2id.numTracks;i++){                                               printf("CD #1: Track = %d length in minutes = %f\n";                i, (float)cd2id.track[i].lengthMs/60000.0);                                   }                                                                             printf("\n");                                                       cdFromDB.track[0]lengthMs = 121323;                                           cdFromDB.track[1]lengthMs = 234565;                                           cdFromDB.track[2]lengthMs = 566437;                                           cdFromDB.track[3]lengthMs = 245120;                                           cdFromDB.track[4]lengthMs = 20000;                                            cdFromDB.track[5]lengthMs = 120386;                                           cdFromDB.numTracks = 6;                                                       for(i=1;i<cdFromDB.numTracks;i++){                                            printf("CD #2: Track = %d length in minutes = %f\n",                i, (float)cdFromDB.track[i].lengthMs/60000.0);                                }                                                                             CreateFuzzyId( &fidcd2id, &cd2id );                                           CreateFuzzyId( &fidcdFromDB, &cdFromDB );                                     matchpercent = FuzzyMatch( &fidcd2id, &fidcdFromDB );                         printf("The cd's matchpercent was computed as=%f",matchpercent);              printf("\n");                                                       printf("\n");                                                       // put in some test values for the cd track lengths                           // since these are in ms, its basically 6000 = 1 minutes                      cd2id.track[0]lengthMs = 34213;                                               cd2id.track[1]lengthMs = 334565;                                              cd2id.track[2]lengthMs = 231423;                                              cd2id.track[3]lengthMs = 134122;                                              cd2id.track[4]lengthMs = 2342;                                                cd2id.track[5]lengthMs = 3487;                                                cd2id.track[6]lengthMs = 9976;                                                cd2id.numTracks = 7;                                                          for(i=1;i<cd2id.numTracks;i++) {                                              printf("CD #1: Track = %d length in minutes = %f\n",                i, (float)cd2id.track[i].lengthMs/60000.0);                                   }                                                                             printf("\n");                                                       cdFromDB.track[0]lengthMs = 121323;                                           cdFromDB.track[1]lengthMs = 234565;                                           cdFromDB.track[2]lengthMs = 566437;                                           cdFromDB.track[3]lengthMs = 245120;                                           cdFromDB.track[4]lengthMs = 20000;                                            cdFromDB.track[5]lengthMs = 120386;                                           cdFromDB.track[6]lengthMs = 323453;                                           cdFromDB.numTracks = 6;                                                       for(i=1;i<cdFromDB.numTracks;i++){                                            printf("CD #2: Track = %d length in minutes = %f\n",                i, (float)cdFromDB.track[i].lengthMs/60000.0);                                }                                                                             CreateFuzzyId( &fidcd2id, &cd2id);                                            CreateFuzzyId( &fidcdFromDB, &cdFromDB);                                      matchpercent = FuzzyMatch( &fidcd2id, &fidcdFrom DB );                        printf ("The cd's matchpercent was computed as=%f",matchpercent);             }                                                                             ______________________________________                                    

                                      APPENDIX B                                  __________________________________________________________________________    /*                                                                             * EXACT MATCH CD ID                                                           * - 1996 ION                                                                  *                                                                             *                                                                             * by Ty Roberts                                                              */                                                                            #include <stdio.h>                                                            #include <stdlib.h>                                                           #include <time.h>                                                             struct cdid {                                                                 long  id[2];                                                                  };                                                                            typedef struct cdid cdid, *cdidPtr;                                           // structure of a cd track with all times stored in milliseconds              struct cdtrack{                                                               long  beginMs;                                                                             // start time in miliseconds                                     long  endMs;     // end time in milliseconds                                  long  lengthMs;                                                                            // length in Miliseconds                                         };                                                                            typedef struct cdtrack cdtrack, *cdTrackPtr;                                  struct cd {                                                                   short numTracks;                                                              cdtrack track[100];                                                           };                                                                            typedef struct cd cd, *cdPtr;                                                 void CreateUniqueId( cdidPtr cid, cdPtr cd );                                 // SUBROUTINES                                                                void CreateUniqueId( cdidPtr cid, cdPtr cd )                                  long    i, t, n;                                                              t = 0;                                                                        n = 0;                                                                        for(i=0;i<cd->numTracks;i++) {                                                // shift left and create a MSB length thats not exact                         t += cd-> track[i].lengthMs;                                                  n += cd-> track[i].beginMs + cd-> track[i].endMs;                             }                                                                             cid->id[0] = t< <10+cd->num Tracks;                                           cid->id[1] = n;                                                                }                                                                            void main(void)                                                               {                                                                             short i;                                                                      short matchtest;                                                              // create global structures for two complete cds with up to 100 tracks        cd    cd2id;                                                                  cdid  cd2UID;                                                                 cd    cdFromDB;                                                               cdid  cdFromDBUID;                                                            printf ("Test #1 will compare two cd that are exactly the                     same\n\n");                                               // put in some test values for the cd track lengths                           // since thes are in ms, its basically 60000 = 1 minute                       cd2id.track[0].beginMs = 0;                                                   cd2id.track[1].beginMs = 100001;                                              cd2id.track[2].beginMs = 231001;                                              cd2id.track[3].beginMs = 345001;                                              cd2id.track[4].beginMs = 435001;                                              cd2id.track[5].beginMs = 460001;                                              cd2id.track[6].beginMs = 590001;                                              cd2id.track[0].endMs = 100000;                                                cd2id.track[1].endMs = 231000;                                                cd2id.track[2].endMs = 345000;                                                cd2id.track[3].endMs = 435000;                                                cd2id.track[4].endMs = 460000;                                                cd2id.track[5].endMs = 590000;                                                cd2id.track[6].endMs = 690000;                                                cd2id.track[0].lengthMs = cd2id.track[0].endMs - cd2id.track[0].beginMs;      cd2id.track[1].lengthMs = cd2id.track[1].endMs - cd2id.track[1].beginMs;      cd2id.track[2].lengthMs = cd2id.track[2].endMs - cd2id.track[2].beginMs;      cd2id.track[3].lengthMs = cd2id.track[3].endMs - cd2id.track[3].beginMs;      cd2id.track[4].lengthMs = cd2id.track[4].endMs - cd2id.track[4].beginMs;      cd2id.track[5].lengthMs = cd2id.track[5].endMs - cd2id.track[5].beginMs;      cd2id.track[6].lengthMs = cd2id.track[6].endMs - cd2id.track[6].beginMs;      cd2id.numTracks = 7;                                                          for(i=1;i<cd2id.numTracks;i++) {                                              printf ("CD #1: Track = %d length inminutes = %f\n", i,             (float)cd2id.track[i].lengthMs/60000.0 );                                     }                                                                             printf("\n");                                                       cdFromDB.track[0].beginMs = 0;                                                cdFromDB.track[1].beginMs = 100001;                                           cdFromDB.track[2].beginMs = 231001;                                           cdFromDB.track[3].beginMs = 345001;                                           cdFromDB.track[4].beginMs = 435001;                                           cdFromDB.track[5].beginMs = 460001;                                           cdFromDB.track[6].beginMs = 590001;                                           cdFromDB.track[0].endMs = 100000;                                             cdFromDB.track[1].endMs = 231000;                                             cdFromDB.track[2].endMs = 345000;                                             cdFromDB.track[3].endMs = 435000;                                             cdFromDB.track[4].endMs = 460000;                                             cdFromDB.track[5].endMs = 590000;                                             cdFromDB.track[6].endMs = 690000;                                             cdFromDB.track[0].lengthMs = cd2id.track[0].endMs - cd2id.track[0].beginMs    ;                                                                             cdFromDB.track[1].lengthMs = cd2id.track[1].endMs - cd2id.track[1].beginMs    ;                                                                             cdFromDB.track[2].lengthMs = cd2id.track[2].endMs - cd2id.track[2].beginMs    ;                                                                             cdFromDB.track[3].lengthMs = cd2id.track[3].endMs - cd2id.track[3].beginMs    ;                                                                             cdFromDB.track[4].lengthMs = cd2id.track[4].endMs - cd2id.track[4].beginMs    ;                                                                             cdFromDB.track[5].lengthMs = cd2id.track[5].endMs - cd2id.track[5].beginMs    ;                                                                             cdFromDB.track[6].lengthMs = cd2id.track[6].endMs - cd2id.track[6].beginMs    ;                                                                             cdFromDb.numTracks = 7;                                                       for(i=1;i<cdFromDB.numTracks;i++) {                                            printf("CD #2: Track = %d length inminutes = %f\n", i,             (float)cdFromDB.track[i].lengthMs/60000.0);                                       }                                                                         CreateUniqueId( &cd2UID, &cd2id );                                            printf( "Unique ID for CD #1 = %d%d\n", cd2UID.id[0],               cd2UID.id[1]);                                                                CreateUniqueId( & cdFrom DBUID, &cdFromDB );                                  printf( "Unique ID for CD #2 = %d%d\n", cdFromDBUID.id[0]           cdFromDBUID.id[1]);                                                           matchtest = (cd2UID.id[0] == cdFromDBUID.id[0]) && (cd2UID.id[1] ==           cdFrom DBUID.id[1]);                                                          printf ("The cd's match if result is non zero matchresult=%d",matchtest);     printf ("\n");                                                      printf ("\n");                                                      printf ("Test #2 will compare two cd that are nearly the                      same\nexcept they have                                              diffent # of tracks \n");                                           // put in some test values for the cd track lengths                           // since thes are in ms, its basically 60000 = 1 minute                       cd2id.track[0].beginMs = 0;                                                   cd2id.track[1].beginMs = 100001;                                              cd2id.track[2].beginMs = 121001;                                              cd2id.track[3].beginMs = 345001;                                              cd2id.track[4].beginMs = 435001;                                              cd2id.track[5].beginMs = 460001;                                              cd2id.track[6].beginMs = 590001;                                              cd2id.track[0].endMs = 100000;                                                cd2id.track[1].endMs = 231000;                                                cd2id.track[2].endMs = 345000;                                                cd2id.track[3].endMs = 435000;                                                cd2id.track[4].endMs = 460000;                                                cd2id.track[5].endMs = 590000;                                                cd2id.track[6].endMs = 690000;                                                cd2id.track[0].lengthMs = cd2id.track[0].endMs - cd2id.track[0].beginMs;      cd2id.track[1].lengthMs = cd2id.track[1].endMs - cd2id.track[1].beginMs;      cd2id.track[2].lengthMs = cd2id.track[2].endMs - cd2id.track[2].beginMs;      cd2id.track[3].lengthMs = cd2id.track[3].endMs - cd2id.track[3].beginMs;      cd2id.track[4].lengthMs = cd2id.track[4].endMs - cd2id.track[4].beginMs;      cd2id.track[5].lengthMs = cd2id.track[5].endMs - cd2id.track[5].beginMs;      cd2id.track[6].lengthMs = cd2id.track[6].endMs - cd2id.track[6].beginMs;      for(i=1;i<cd2id.numTracks;i++){                                               printf("CD #1: Track = %d length inminutes = %f\n", i,              (float)cd2id.track[i]lengthMs/60000.0);                                       }                                                                             printf ("\n");                                                      cdFromDB.track[0].beginMs = 0;                                                cdFromDB.track[1].beginMs = 100001;                                           cdFromDB.track[2].beginMs = 231001;                                           cdFromDB.track[3].beginMs = 345001;                                           cdFromDB.track[4].beginMs = 435001;                                           cdFromDB.track[5].beginMs = 460001;                                           cdFromDB.track[6].beginMs = 590001;                                           cdFromDB.track[0].endMs = 100000;                                             cdFromDB.track[1].endMs = 231000;                                             cdFromDB.track[2].endMs = 345000;                                             cdFromDB.track[3].endMs = 435000;                                             cdFromDB.track[4].endMs = 460000;                                             cdFromDB.track[5].endMs = 590000;                                             cdFromDB.track[0].lengthMs = cdFromDB.track[0].endMs - cdFromDB.track[0].b    eginMs;                                                                       cdFromDB.track[1].lengthMs = cdFromDB.track[1].endMs - cdFromDB.track[1].b    eginMs;                                                                       cdFromDB.track[2].lengthMs = cdFromDB.track[2].endMs - cdFromDB.track[2].b    eginMs;                                                                       cdFromDB.track[3].lengthMs = cdFromDB.track[3].endMs - cdFromDB.track[3].b    eginMs;                                                                       cdFromDB.track[4].lengthMs = cdFromDB.track[4].endMs - cdFromDB.track[4].b    eginMs;                                                                       cdFromDB.track[5].lengthMs = cdFromDB.track[5].endMs - cdFromDB.track[5].b    eginMs;                                                                       cdFromDB.numTracks = 6;                                                       for(i=1; i<cdFromDB.numTracks;i++) {                                          printf ("CD #2: Track = %d length in minutes = % f\n", i,           (float)cdFromDB.track[i].lengthMs/60000.0);                                   }                                                                             CreateUniqueID(&cd2UID, &cd2id );                                             printf("Unique ID for CD #1 = %d%d\n", cd2UID.id[0];                cd2UID.id[1]);                                                                CreateUniqueID(&cdFromDBUID, %cdFromDB );                                     printf("Unique ID for CD #2 = %d%d\n, cdFrom DBUID.id[0];           cdFromDBUID.id[1];                                                            matchtest = (cd2UID.id[0] == cdFromDBUID.id[0]) && (cd2UID.id[1] ==           cdFromDBUID.id[1]);                                                           printf("The cd's match if result is non zero match result=%d",matchtest);     printf ("\n");                                                      printf ("\n");                                                      }                                                                             __________________________________________________________________________

What is claimed is:
 1. At least one computer program stored on acomputer-readable medium, embodying a method of searching for a match ina database of a plurality of records, where the records in the databaseinclude length information and number of segments for recordingscorresponding to the records, comprising:calculating approximate lengthinformation for the records in the database and for a selected recordinghaving a number of segments; and determining at least one approximatelymatching record in the database for the selected recording based on thenumber of segments and the approximate length information.
 2. A methodof searching for a match in a database of a plurality of records, wherethe records in the database include length information and number ofsegments for recordings corresponding to the records,comprising:calculating approximate length information for the records inthe database and for a selected recording having a number of segments;and determining at least one approximately matching record in thedatabase for the selected recording based on the number of segments andthe approximate length information.
 3. A method as recited in claim2,wherein the length information for the records in the database and forthe selected recording includes information indicating the length ofeach segment, and wherein said determining includes comparing the lengthof corresponding segments in the selected recording and the at least oneapproximately matching record in the database.
 4. A method as recited inclaim 3, wherein said determining obtains a value indicative of adifference in length between corresponding segments of the selectedrecording and the at least one approximately matching record in thedatabase.
 5. A method as recited in claim 2, further comprisingreceiving a query to search for a match between the selected recordingand the records in the database, the query including the number ofsegments and the length information for the selected recording.
 6. Amethod as recited in claim 5, wherein the recordings corresponding tothe records in the database and the selected recording each contain atleast an audio portion and the number of segments are the number oftracks in the audio portion.
 7. A method as recited in claim 6, whereinthe recordings are compact discs.
 8. A method as recited in claim 6,wherein the recordings are digital versatile discs.
 9. A method asrecited in claim 5,wherein the selected recording is played at a firstlocation, and wherein said method further comprises:generating the queryby a computer at a first location where the selected recording is beingplayed; and sending the query to a server at a second location, remotefrom the first location, where the database is stored.
 10. A method asrecited in claim 9, further comprising sending from the server to thecomputer additional information stored in the at least one approximatelymatching record and not included in the selected recording.
 11. A methodas recited in claim 2, wherein the recordings corresponding to therecords in the database and the selected recording each contain at leastan audio portion and the number of segments are the number of tracks inthe audio portion.
 12. A method as recited in claim 11, wherein therecordings are compact discs.
 13. A method as recited in claim 11,wherein the recordings are digital versatile discs.
 14. A databasesystem, comprising:a storage unit storing a database of a plurality ofrecords, where the records in the database include length informationand number of segments for recordings corresponding to the records; anda processing unit, coupled to said storage unit, programmed to calculateapproximate length information for the records in the database and for aselected recording having a number of segments, and to determine atleast one approximately matching record in the database for the selectedrecording based on the number of segments and the approximate lengthinformation.
 15. A database system as recited in claim 14,wherein thelength information for the records in the database and for the selectedrecording includes information indicating the length of each segment,and wherein said processing unit compares the length of correspondingsegments in the selected recording and the at least one approximatelymatching record in the database.
 16. A database system as recited inclaim 15, wherein said processing unit obtains a value indicative of adifference in length between corresponding segments of the selectedrecording and the at least one approximately matching record in thedatabase.
 17. A database system as recited in claim 14, furthercomprising a communication unit, coupled to said storage unit, toreceive a query to search for a match between the selected recording andthe records in the database, the query including the number of segmentsand the length information for the selected recording.
 18. A databasesystem as recited in claim 17, wherein the recordings corresponding tothe records in the database and the selected recording each contain atleast an audio portion and the number of segments are the number oftracks in the audio portion.
 19. A database system as recited in claim18, wherein the recordings are compact discs.
 20. A database system asrecited in claim 18, wherein the recordings are digital versatile discs.21. A database system as recited in claim 17,wherein said processingunit, storage unit and communication unit are at a first location, andwherein said database system further comprises:a computer at a secondlocation, remote from the first location, to generate the query and playthe selected recording; and a communication network at least temporarilycoupling said computer and said communication unit to send the queryfrom said computer to said communication unit.
 22. A database system asrecited in claim 21, wherein said communication unit sends to thecomputer via said communication network additional information stored inthe at least one approximately matching record and not included in theselected recording.
 23. A method as recited in claim 14, wherein therecordings corresponding to the records in the database and the selectedrecording each contain at least an audio portion and the number ofsegments are the number of tracks in the audio portion.
 24. A method asrecited in claim 23, wherein the recordings are compact discs.
 25. Amethod as recited in claim 23, wherein the recordings are digitalversatile discs.
 26. At least one computer program as recited in claim1, wherein the recordings corresponding to the records in the databaseand the selected recording each contain at least an audio portion andthe number of segments are the number of tracks in the audio portion.27. At least one computer program as recited in claim 1,wherein thelength information for the records in the database and for the selectedrecording includes information indicating the length of each segment,and wherein said determining includes comparing the length ofcorresponding segments in the selected recording and the at least oneapproximately matching record in the database.
 28. At least one computerprogram as recited in claim 27, wherein said determining obtains a valueindicative of a difference in length between corresponding segments ofthe selected recording and the at least one approximately matchingrecord in the database.
 29. At least one computer program as recited inclaim 1, further comprising receiving a query to search for a matchbetween the selected recording and the records in the database, thequery including the number of segments and the length information forthe selected recording.
 30. At least one computer program as recited inclaim 29, wherein the recordings corresponding to the records in thedatabase and the selected recording each contain at least an audioportion and the number of segments are the number of tracks in the audioportion.
 31. At least one computer program as recited in claim 30,wherein the recordings are compact discs.
 32. At least one computerprogram as recited in claim 30, wherein the recordings are digitalversatile discs.
 33. At least one computer program as recited in claim29,wherein the selected recording is played at a first location, andwherein said method further comprises:generating the query by a computerat a first location where the selected recording is being played; andsending the query to a server at a second location, remote from thefirst location, where the database is stored.
 34. At least one computerprogram as recited in claim 33, further comprising sending from theserver to the computer additional information stored in the at least oneapproximately matching record and not included in the selectedrecording.
 35. At least one computer program as recited in claim 26,wherein the recordings are digital versatile discs.
 36. At least onecomputer program as recited in claim 26, wherein the recordings arecompact discs.